tech 1 Scan Tool
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 |
Important: The coolant flow may be interrupted at times because of the thermostat closing during engine warm-up. Is there coolant flow through the radiator assembly present at or before 100°C (212°F)? | -- | ||
2 | The condition is caused from something other than a faulty thermostat. Is there still an overheat or boiling condition? | -- | Go to Engine Overheating | -- |
3 |
Is there still an overheat or boiling condition? | -- | -- | System OK |
Step | Action | Value | Yes | No | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
DEFINITION: The engine temperature lamp comes on and stays on, or the temperature gauge shows hot, or coolant overflows from the coolant recovery reservoir onto the ground while the engine is running. | ||||||||||||
1 | Check for a loss of coolant. Is there a loss of coolant? | -- | ||||||||||
2 | Fill the system to the specified level. Refer to Cooling System Draining and Filling . Does the engine still overheat? | -- | System OK | |||||||||
3 | Check the engine oil level. Is the engine oil level too high? | -- | ||||||||||
4 | Correct the engine oil level as necessary. Does the engine still overheat? | -- | System OK | |||||||||
5 | Check for the following missing or damaged parts:
Are there any missing or damaged deflectors, baffles, or shrouds? | -- | ||||||||||
6 | Repair or replace any deflectors, baffles, or shrouds as necessary.
Does the engine still overheat? | -- | System OK | |||||||||
7 | Check the coolant concentration. Refer to Coolant Concentration Testing . Is the coolant concentration adequate? | -- | ||||||||||
8 | Correct the coolant concentration as necessary. Refer to Notice: Pure coolant can be added to raise the boiling point of the coolant, but too much will affect the freezing point. Do not use a solution stronger than 70 percent, as the freeze level rises rapidly after this point. Pure coolant will freeze at -22°C (-8°F). .Does the engine still overheat? | -- | System OK | |||||||||
9 | Check for a loss of cooling system pressure. Does the cooling system maintain the correct pressure? | -- | ||||||||||
10 | Pressure test the cooling system. Correct as necessary. Refer to Cooling System Leak Testing . Does the engine still overheat? | 103 kPa (15 psi) | System OK | |||||||||
11 | Check for a pinched or kinked coolant recovery reservoir hose. Is the reservoir hose kinked or damaged? | -- | ||||||||||
12 | Reroute or replace the hose as necessary. Does the engine still overheat | -- | System OK | |||||||||
13 | Check the fan belt tension (RPO VO8 heavy-duty cooling system). Refer to Engine Mechanical. Is the fan belt tensioned properly? | -- | ||||||||||
14 | Correct the fan belt tension as necessary. Does the engine still overheat? | -- | System OK | |||||||||
15 | Check for an exhaust system restriction (plugged catalytic converters). Is there a restriction in the exhaust system? | -- | ||||||||||
16 | Correct the restriction as necessary. Refer to Exhaust. Does the engine still overheat? | -- | System OK | |||||||||
17 | Check for an obstructed radiator air flow or bent fins. Are any radiator fins bent or is air flow to the radiator being obstructed? | -- | ||||||||||
18 | Remove or relocate add on parts that block air flow to the radiator. Refer to Cooling System . Does the engine still overheat? | -- | System OK | |||||||||
19 | Check for a blockage in the cooling system passages. Are the cooling system passages blocked? | -- | ||||||||||
20 |
Does the engine still overheat? | -- | System OK | |||||||||
21 | Check for an inoperative cooling fan or a cooling fan operating in reverse (fan forcing hot air from engine compartment through the radiator). Are any cooling fans inoperative or operating in reverse? | -- | ||||||||||
22 | Refer to Emissions or reverse the polarity at the fan motor connector terminals. Does the engine still overheat? | -- | System OK | |||||||||
23 | Check for an inoperative mechanical fan blade clutch (RPO VO8 heavy-duty cooling systems only). Is the fan blade clutch inoperative | -- | ||||||||||
24 | Replace the fan blade clutch. Refer to Fan Clutch Replacement . Does the engine still overheat? | -- | System OK | |||||||||
25 | Check for an inoperative or damaged fan blade (RPO VO8 heavy-duty cooling system) or engine cooling fan. Is the fan blade/cooling fan damaged or incorrect? | -- | ||||||||||
26 |
| -- | System OK | |||||||||
27 | Check if the thermostat is stuck in the closed position. Refer to Engine Overheating . Is the thermostat sticking (or stuck) in the closed position? | -- | ||||||||||
28 | Replace the thermostat. Refer to Engine Coolant Thermostat Replacement . Does the engine still overheat? | -- | System OK | |||||||||
29 | Check for a faulty coolant pump. Is the coolant pump faulty? | -- | ||||||||||
30 | Replace the coolant pump as necessary. Refer to Engine Mechanical. Does the engine still overheat? | -- | System OK | |||||||||
31 | Check the radiator cooling capacity. Make sure the proper sized radiator is being used on the cooling system. Is the correct sized radiator being used with the cooling system? | -- | System OK | |||||||||
32 | If necessary, install the correct radiator. Refer to Radiator Replacement . Does the engine still overheat? | -- | -- | System OK |